Azetidinedione urethanes

ABSTRACT

Novel isocyanato-azetidinedione compounds are provided which have the formula ##STR1## wherein R and R 1  can be independently selected from hydrogen and hydrocarbyl or can be joined together and along with the carbon to which they are attached represent a cycloalkane residue having 4 to 6 ring carbon atoms, y is an integer from 1 to 7 and X is a hydrocarbon radical having a valency of y plus one. 
     The monoisocyanate compounds are used as intermediates to provide further novel azetidinedione containing derivatives in the form of azetidinedione-isocyanurates (II) and azetidinedione-urethanes (III). 
     All three classes of compounds can be employed as acid scavenging agents for stabilizing various kinds of halogenated polymer systems. Notably, (I) and (III) form highly useful polyamide-polyureas and polyamide-polyurethanes respectively by reaction with organic polyamines.

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional of application Ser. No. 608,005 filed May 7, 1984,now U.S. Pat. No. 4,576,747.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to azetidinediones and is more

particularly concerned with novel isocyanato-azetidinediones andparticular azetidinedione-isocyanurates and azetidinedione-urethanesprepared from said isocyanatoazetidinediones.

2. Description of the Prior Art

Various azetidine-2,4-dione compounds have been described in the art;for typical disclosures of such compounds see U.S. Pat. No. 3,265,684,Ebnother et al, Helvetica Chemica Acta, 42, 1959, pp 918 to 955, andMartin et al, J. of Organic Chemistry, 36, 1971, pp 2205 to 2210.

I have now discovered what I believe to be a novel class ofisocyanato-azetidinediones defined below. These compounds possess adegree of stability in the azetidinedione ring which allows for theirconversion to other azetidinedione ring containing compounds without theopening of the ring or polymerization thereof. Such stability would nothave been predictable from the prior art.

SUMMARY OF THE INVENTION

This invention comprises isocyanato-azetidinediones having the formula(I) ##STR2## wherein R and R₁ when taken individually are independentlyselected from the group consisting of hydrogen and hydrocarbyl, and Rand R₁, when taken together with the carbon atom to which they areattached, represent a cycloalkane residue having 4 to 6 ring carbonatoms, inclusive, y is an integer from 1 to 7, and X is a hydrocarbonradical having a valency of y plus one.

The invention also comprises azetidinedioneisocyanurates having theformula (II) and azetidinedioneurethanes having the formula (III)##STR3## wherein each A represents the group ##STR4## wherein R and R₁have the same significance as set forth above, R₂ is the residue of ahydroxyl compound containing m hydroxyl groups wherein the value of m isfrom about 1 to about 8, and X is the divalent form of the hydrocarbonradical X defined above.

The term "hydrocarbyl" means the monovalent radical obtained by removingone hydrogen atom from the parent hydrocarbon having from 1 to 18 carbonatoms. Illustrative of hydrocarbyl are alkyl such as methyl, ethyl,propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, hexadecyl,octadecyl, and the like, including isomeric forms thereof; alkenyl suchas vinyl, allyl, butenyl, pentenyl, hexenyl, octenyl, decenyl,undecenyl, tridecenyl, hexadecenyl, octadecenyl, and the like, includingisomeric forms thereof; aralkyl such as benzyl, phenylethyl,phenylpropyl, benzhydryl naphthylmethyl, and the like; aryl such asphenyl, tolyl, xylyl, naphthyl, biphenylyl, and the like; cycloalkylsuch as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl,and the like including isomeric forms thereof; and cycloalkenyl such ascyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, and the like,including isomeric forms thereof.

The hydrocarbyl groups which form the groups R and R₁ can be substitutedby one or a plurality of substituents provided the latter are notreactive with the azetidinedione ring common to formulae (I), (II), and(III), the isocyanate groups of (I), the isocyanurate ring of (II), andurethane linkages of (III). Illustrative of such substituents are halo,i.e. chloro, bromo, fluoro, and iodo; nitro; alkoxy from 1 to 8 carbonatoms, inclusive, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy,hexyloxy, heptyloxy, octyloxy, and the like, including isomeric formsthereof; alkylmercapto from 1 to 8 carbon atoms, inclusive, such asmethylmercapto, ethylmercapto, propylmercapto, butylmercapto,pentylmercapto, hexylmercapto, heptylmercapto, octylmercapto, and thelike, including isomeric forms thereof; and cyano.

The term "cycloalkane having 4 to 6 ring carbon atoms" is inclusive ofcyclobutane, 3-methylcyclobutane, cyclopentane, 3-methylcyclopentane,cyclohexane, 3-methylcyclohexane, 4-methylcyclohexane, and the like.

The term "hydrocarbon radical having a valency of y plus one" means thedivalent, trivalent, tetravalent, pentavalent, hexavalent, heptavalent,and octavalent radical obtained by removing two, three, four, five, six,seven or eight hydrogen atoms from the parent hydrocarbon having acarbon atom content of from 2 to 36, inclusive, such as alkylene,cycloalkylene, arylene, divalent radicals having the formula ##STR5##wherein V is selected from the group consisting of --CO--, --O--, --SO₂--, and alkylene having 1 to 4 carbon atoms, inclusive, andpolymethylene polyphenylene radicals having the formula ##STR6## whereinz is 0 or a number having an average value from 0 to 1.

DETAILED DESCRIPTION OF THE INVENTION Isocyanato-Azetidinediones (I)

The novel isocyanato-azetidinediones in accordance with the presentinvention are defined by the formula (I) above. They exhibit goodsolubility in the common organic solvents such as ethers, for example,dibutyl ether, dioxane, and the like; esters, for example, ethylacetate, butyl acetate, and the like; ketones, for example, acetone,methylethyl ketone, and the like; chlorinated solvents, for example,chloroform, carbon tetrachloride, and the like; aromatic solvents, forexample, benzene, toluene, xylene, and the like; and dipolar aproticsolvents, for example, acetonitrile, dimethylacetamide, and the like.They are generally less soluble in the low molecular weight aliphaticand cycloaliphatic hydrocarbons (pentane, hexane, cyclohexane, and thelike).

The compounds (I) are further characterized by strong absorption in theinfrared at from about 1710 cm⁻¹ to about 1745 cm⁻¹ and weakerabsorption at 1859 cm⁻¹ due to the carbonyl groups at the 2 and 4positions of the azetidinedione ring, and by strong absorption at about2275 cm⁻¹ due to the isocyanate group(s).

Illustrative but not limiting of the isocyanatoazetidinediones (I) inaccordance with the present invention areN-(6-isocyanatohexyl)azetidine-2,4-dione,N-(6-isocyanatohexyl)-3,3-dimethylazetidine-2,4-dione,N-(6-isocyanatohexyl)-3,3-diethylazetidine-2,4-dione,N-(6-isocyanatohexyl)-3-ethyl-3-butylazetidine-2,4-dione,N-(6-isocyanatohexyl)-3-methyl-3-allylazetidine-2,4-dione,N-(6-isocyanatohexyl)-3-benzylazetidine-2,4-dione,N-(6-isocyanatohexyl)-3-phenylazetidine-2,4-dione,N-(6-isocyanatohexyl)-3,3-pentamethyleneazetidine-2,4-dione,N-(3-isocyanatocyclopentyl)-3,3-dimethylazetidine-2,4-dione,N-(4-isocyanatocyclohexyl)-3,3-dimethylazetidine-2,4-dione,N-(4-isocyanatocyclohexyl)-3-ethyl-3-butylazetidine-2,4-dione,N-(4-isocyanatophenyl)-3,3-dimethylazetidine-2,4-dione,N-(4-isocyanatophenyl)-3,3-dibutylazetidine-2,4-dione,N-(4-isocyanatophenyl)-3-ethyl-3-butylazetidine-2,4-dione,N-(3-isocyanato-4-methylphenyl)-3,3-dimethylazetidine-2,4-dione,N-(3-isocyanato-4-methylphenyl)-3,3-diethylazetidine-2,4dione,N-(3-isocyanato-4-methylphenyl)-3-ethyl-3-butyl-azetidine-2,4-dione,N-(3-isocyanato-6-methylphenyl)-3,3-dimethylazetidine-2,4-dione,N-(3-isocyanato-6-methyl-phenyl)-3-ethyl-3-butylazetidine-2,4-dione,N-(2-methyl-3-isocyanatophenyl)-3,3-dimethylazetidine-2,4-dione,N-(2-methyl-3-isocyanatophenyl)-3,3-diethylazetidine-2,4-dione,N-(2-methyl-3-isocyanatophenyl)-3-ethyl-3-butylazetidine-2,4-dione,4-isocyanato-4'-(3,3-dimethyl-2,4-dioxo-azetidino)diphenylmethane,4-isocyanato-4'-(3,3-diethyl-2,4-dioxo-azetidino)diphenylmethane,4-isocyanato-4'-(3,3-dipropyl-2,4-dioxo-azetidino)diphenylmethane,4-isocyanato-4'-(3-ethyl-3-butyl-2,4-dioxoazetidino)diphenylmethane,4-isocyanato-4'-(3-benzyl-2,4-dioxo-azetidino)diphenylmethane,4-isocyanato-4'-(3-phenyl-2,4-dioxo-azetidino)diphenylmethane,4-isocyanato-4'-(3,3-pentamethylene-2,4-dioxo-azetidino)diphenylmethane,and the like; and the polyisocyanato-azetidinediones wherein theequivalent of about one isocyanate group intriphenylmethane-4,4',4"-triisocyanate, 1,6,11-undecane triisocyanate,or a polymethylene polyphenyl polyisocyanate having an equivalent weightof about 130 to about 160, is replaced by a 3,3-dimethyl-, 3,3-diethyl-,or 3-ethyl-3-butyl-2,4-dioxo-azetidino radical.

The isocyanato-azetidinediones are prepared by processes which areanalogous to those known in the art. Illustratively, the compounds canbe prepared using a procedure analogous to that set forth in U.S. Pat.No. 3,265,684, cited supra, according to the following equation:##STR7##

The acid chloride (bromide, iodide, or fluoride can also be used)starting materials (IV) are well known and readily available compoundswherein R and R₁ have the significance set forth above.

The isocyanate reactants (V) wherein X and y have the same significanceas set forth above can be any of the known polyfunctional organicisocyanates A preferred group of the polyisocyanates which can beemployed are hexamethylene diisocyanate; 1,4-cyclohexylene diisocyanate,methylenebis(cyclohexyl isocyanate), isophorone diisocyanate;methylenebis(phenyl isocyanate) including the 4,4'- and 2,4'-isomers andmixtures thereof, m- and p-phenylene diisocyanates, 2-chloro-p-phenylenediisocyanate, 2,4- and 2,6-toluene diisocyanate and mixtures thereof,1,5-naphthalene diisocyanate, 1,6,11-undecane triisocyanate,triphenylmethahe-4,4',4"-triisocyanate, the liquefied forms ofmethylenebis(phenyl isocyanate) such as those described in U.S. Pat. No.3,384,653; and the polymethylene polyphenyl polyisocyanates.

The proportions in which the acid halide (IV) and isocyanate (V) arereacted together are not critical but are preferably about equimolar,and, most preferably the isocyanate is employed in up to 100 percentmole excess over the acid halide concentration.

The reaction is carried out by heating the reactants together in aninert organic solvent at a temperature of at least about 75° C. in thepresence of an acid halide acceptor, preferably, a tertiary organicamine such as triethyl amine, tributyl amine, pyridine, and the like.The term "inert organic solvent" means an organic solvent which does notinteract with the reactants or the product or otherwise interfere withthe reaction Illustrative of the solvents which can be employed are thesolvents set forth above in which the products are soluble.

The progress and completion of the reaction can be easily monitored byconventional analytical procedures such as by infrared spectroscopy,nuclear magnetic resonance spectroscopy, and like analytical methods.

Generally speaking, the hydrohalide salt of the tertiary amineprecipitates from solution and is readily removed by filtration. Thesolvent is removed by standard methods such as distillation either atatmospheric or reduced pressure to yield the product. The latter can bepurified, if desired, by routine procedures such as distillation and/orrecrystallization, chromatography and the like.

The compounds of formula (I) all possess the property of forming highlyuseful polyamide-polyurea copolymers when polymerized with organicpolyamines. The isocyanate groups react with the amine function in thewell known manner to form the urea linkages. The amide linkages areformed from the facile opening of the azetidinedione ring by the amine.Accordingly, typical copolymers are formed in accordance with thefollowing representative schematic equation wherein the compound (I) isa monoisocyanate (Ia) and the polyamine is a diamine, ##STR8## wherein Bis the organic residue of the polyamine.

It will be understood by one skilled in the art that the above equationand recurring unit produced thereby are illustrative only of the lineartypes of polymers that can be prepared. When y in (I) is greater than 1and/or the polyamine has a functionality greater than 2 thencross-linked polymers will result.

The polymerization process can be carried out using any prior artmethods for reacting polyamines with polyisocyanates to preparepolyureas. For example, see U.S. Pat. Nos. 4,296,212; 4,374,210 and4,433,067 for typical reactants and procedures and whose disclosures areherein incorporated by reference. The copolymers can be prepared inbulk, cast, or molded form depending on the end-use desired, thepresence or absence of other ingredients, and the like.

Generally speaking, the compound (I) and the polyamine are polymerizedin substantially equivalent amounts wherein the term "equivalent" inreference to both reactants refers to their molecular weights divided bytheir respective functionalities. The term "functionality" in referenceto the polyamines is simply the number of amine groups whereas inreference to (I) the azetidinedione ring serves as one functional groupwhile the isocyanate(s) serves as the other funtional group(s).

Illustratively, the organic polyamines can have an amine functionalityof from 2 to 6 and a molecular weight of from about 60 to about 5000;such as ethylene diamine, butylene diamine, amine terminated polyetherpolyols having 2 or 3 primary or secondary amine groups and a molecularweight of from about 1000 to about 4000.

Most useful of the polyamide-polyurea copolymers are the linear onesprepared from the difunctional compounds (Ia) and the organic diamines.

The polyamide-polyurea copolymers can be rapidly molded to form autoparts such as bumpers, body elements, panels, doors, engine hoods,skirts, air-scoops, and the like.

Also the compounds (I) in accordance with the present invention areuseful as acid and water scavenging agents for stabilizing various kindsof halogenated polymer systems such as chlorinated polymers andparticularly polyvinyl chloride. The monoisocyanates (Ia) areparticularly useful for the preparation of the novelazetidinedione-isocyanurates (II) and azetidine-dione-urethanes (III)discussed below.

Azetidinedione-isocyanurates (II) ##STR9##

The novel azetidinedione-isocyanurates (II) in accordance with thepresent invention are obtained via the trimerization of themonoisocyanato-azetidinediones (Ia) as set forth in the above reactionscheme wherein X, R, and R₁ are defined above.

The azetidinedione-isocyanurate compounds can be used as acid scavengingagents for stabilizing the same types of halogenated polymer systemsreferred to above.

The preferred class of monoisocyanates (Ia) for the trimerization to(II) is the one wherein X is a divalent hydrocarbon radical, and,particularly, an arylene radical or a radical having the formula##STR10## defined above and R and R₁ are the same or different alkylgroups.

Illustrative but not limiting of the monoisocyanates which are readilytrimerized to the isocyanurates (II) are themonoisocyanate-azetidinediones exemplified above.

Preferred species for the trimerization to (II) are thosemonoisocyanates exemplified above wherein X is 4-methylphenylene,6-methylphenylene, and mixtures thereof, and 4,4'-methylenebisphenylene.

The trimerization process is carried out using any of the methods andtechniques well known to those skilled in the art; for illustrativemethods see Saunders and Frisch, Polyurethanes Chemistry and Technology,Part I, 1962, pp 94 to 95, Interscience Publishers, New York, N.Y., andU.S. Pat. Nos. 2,979,485; 2,993,870 and 3,381,008 whose patentdisclosures are incorporated herein by reference.

The trimerization is preferably carried out in the presence of an inertsolvent, i.e. a solvent that does not react with isocyanate groups orotherwise interfere with the course of the trimerization. Preferredsolvents are aromatic solvents such as benzene, toluene, xylene,nitrobenzene, chlorobenzene and the like, and aliphatic esters such asethyl acetate, butyl acetate, and the like.

Advantageously, the trimerization is carried out at a temperaturefalling within a range of about 50° C. to about 200° C., preferablyabout 75° C. to about 150° C. and in the presence of a trimerizationcatalyst.

Any of the catalysts known in the art for the trimerization ofisocyanates may be employed. Typical are those disclosed in thefollowing: The Journal of Cellular Plastics, November/December 1975, p329; U.S. Pat. Nos. 3,745,133; 3,896,052; 3,899,443; 3,903,018;3,954,684 and 4,126,742, and mixtures of any of the catalysts disclosedtherein. The disclosures of these patent references are incorporatedherein by reference.

A preferred group of catalysts comprises the alkali metal salts of loweralkanoic acids such as the sodium, potassium, or lithium salts of formicacid, acetic acid, propionic acid, butyric acid, heptanoic acid,2-methylhexanoic acid, 2-ethylhexanoic acid, and the like.

The catalyst concentration is not critical, and, advantageously, fallswithin a range of from about 0.1 part to about 10 parts by weight perequivalent of isocyanate.

Surprisingly, the azetidinedione ring remains stable under theconditions of the trimerization process which includes high temperatures(as high as 170° C.) while in the presence of the strongly basictrimerization catalysts. This is highly unexpected as the azetidinedionering is known to open readily under basic conditions. Also, the closelyrelated β-lactams (azetidinones) readily ring-open and polymerize undermild basic conditions because of the steric strain in a 4-membered ring.Certain trimerization catalysts, such as the very strongly basic oneslike potassium tertiary butoxide and sodium methoxide, do tend to causesome ring decomposition during trimerization. However, the majority ofthe trimerization catalysts provide the desired products.

Generally speaking, the isocyanurate products are solids and are easilyisolated from their reaction solutions by removing the solvent usingknown methods.

Azetidinedione-urethanes (III)

    Ia+R.sub.2 (OH)m→III

The novel azetidine-urethanes (III) in accordance with the presentinvention are obtained via the reaction of themonoisocyanato-azetidinediones (Ia) defined above with the hydroxylcompounds defined by the formula R₂ (OH)m as shown in the equation setforth above and using the appropriate stoichiometric proportions of theisocyanate to react with substantially all of the hydroxylfunctionality. Any of the well known procedures in the art for reactingisocyanate compounds with hydroxyl containing compounds to formurethanes and polyurethanes, either with or without solvent, can beemployed in preparing the compounds (III) in accordance with the presentinvention. For detailed methods and illustrative techniques for urethanepreparation see Saunders and Frisch, Polyurethanes Chemistry andTechnology, Part I cited supra and also Part II of the same series.

The hydroxyl compounds which can be employed include any of the primaryand secondary hydroxyl containing compounds having a MW from about 32 toabout 5000 such as the aliphatic, aromatic and cycloaliphaticmono-alcohols and organic polyols having a functionality of from 2 to 8.Typical mono-alcohols but not limiting thereof are methanol, ethanol,butanol, phenol, cyclohexanol, and the like.

Of the organic polyols the functionality is preferably from 2 to 3, andmost preferably 2. A preferred molecular weight range is from about 60to about 3000.

A preferred class of polyhydric alcohols are the low molecular weightalkylene glycols, i.e., ethylene glycol, 1,4-butanediol,1,5-pentanediol, 1,6-hexanediol, diethylene glycol, and the like; andthe polyalkyleneoxy glycols of MW range of about 200 to about 2000 suchas polyethyleneoxy glycols, polypropyleneoxy glycols,polyethyleneoxy-polypropyleneoxy glycols, and polytetramethyleneoxyglycols.

Surprisingly, even at elevated reaction temperatures and in the presenceof urethane catalysts, the azetidinedione ring remains stable to thehydroxyl groups of the polyol component and does not polymerize withthem.

The products are characterized by strong infrared absorption at about1740 cm⁻¹ and weaker absorptions at 1850 cm⁻¹ due to the azetidinedionerings.

The urethane products range from viscous liquids to solids (bothcrystalline and amorphous) depending largely on the molecular weight andfunctionality of the polyol employed. If the preparation is carried outin the absence of solvent the product can be obtained directly.Otherwise the products are easily isolated from their reaction solutionsusing known methods.

The compounds of formula (III) wherein m is greater than one, similarlyto those of (I) discussed above, react readily with organic polyamines,and, in this case, to form highly useful polyamide-polyurethanecopolymers. Again, for ease of illustration only, the followingschematic equation sets forth the linear copolymer recurring unitobtained from the polymerization of a compound (III) wherein m=2 with anorganic diamine. ##STR11##

The polyamine has the same significance discussed above and the samepreparative procedures and teaching referred to above for thepolyamide-polyureas applies to the preparation of thepolyamide-polyurethanes. In respect of the equivalent weight of thecompound (III) it refers to the molecular weight of the compound dividedby its number of azetidinedione rings which latter represent functionalgroups.

Most useful of the polyamide-polyurethanes are the linear ones.

The polyamide-polyurethanes can be molded to form the same types of autoparts described above for the polyamide-polyureas.

The compounds (III) wherein m equals one are useful as acid scavengingagents for the stabilization of halogenated polymers.

The following examples describe the manner and process of making andusing the ivention and set forth the best mode contemplated by theinventor of carrying out the invention but are not to be construed aslimiting.

EXAMPLE 1

A 2 liter three-necked reaction flask equipped with a stirrer, refluxcondenser, thermometer, addition funnel, and gas inlet tube was chargedwith a solution of 105 g. (0.6 mole) of 2,4-toluene diisocyanate and 45g. (0.42 mole) of isobutyryl chloride dissolved in 500 ml. of xylene.The solution was stirred and heated in an oil bath to a temperature of115° to 120° C.

A solution of 65 g. (0.64 mole) of triethylamine dissolved in 50 ml. ofxylene was added dropwise to the reaction solution through the additionfunnel and under a nitrogen atmosphere over a 4 hour period. Heating ofthe stirred solution was continued for a further 3 hour period. Thesolution was cooled to about 0° C. and the precipitated solid oftriethylamine hydrochloride was separated by filtration. The filter cakewas washed with fresh xylene and these washings added to the filtrate.

The filtrate and washings were distilled to remove the solvent using arotary evaporator under a pressure of about 15 mm. of mercury and atemperature of about 70° C. An oily residue was obtained. The oil wasvacuum distilled using a short Vigreux column under a pressure of 0.08mm. of mercury. The first fraction, b.p.=60°-120° C., wt.=41.4 g., was a39 percent recovery of starting 2,4-toluene diisocyanate; the secondfraction, b.p.=120°-145° C., wt.=63.1 g. solidified on standing,m.p.=58° to 70° C. Recrystallization of the latter product from 50 ml.of cyclohexane provided 44.2 g. of crystalline solid, m.p.=71°-80° C.representing a 45 percent yield of an isocyanato-azetidinedione mixtureof the two isomeric compounds (a)N-(3-isocyanato-4-methylphenyl)-3,3-dimethylazetidine-2,4-dione and (b)N-(3-isocyanato-6-methylphenyl)-3,3-dimethylazetidine-2,4-dione inaccordance with the present invention and having the formulae ##STR12##

The NMR integration showed that the proportion of isomer (a) to isomer(b) in the reaction product was 60/40 respectively. The isomer (a) wasseparated by repeated recrystallization from cyclohexane with (a) havingthe higher m.p.=89° C.

Elemental analysis for isomer (a): Calculated for C₁₃ H₁₂ N₂ O₃ :C=63.93%, H=4.95%, N=11.47%; Found: C=63.84%, H=5.08%, N=11.31%.

Infrared for mixture of (a) and (b) (CCl₄) (in cm⁻¹): 2960, 2910,2275(s), 1859, 1741(s), 1605, 1512, 1390(s), 1375, and 1040.

Proton nuclear magnetic resonance for isomer (a) (CDCl₃): δ 6 7.52(multiplet, 2 protons), 7.00-7.28 (m,l) 7.34 (singlet,3), 2.36 (s, 3),1.50 and 1.45 (s,6).

EXAMPLE 2

Using a similar procedure and apparatus as described in Example 1 excepton a smaller scale, a stirred solution of 17.5 g. (0.1 mole) of2,4-toluene diisocyanate and 20.0 g. (0.15 mole) of α-ethylbutyrylchloride dissolved in 125 ml. of xylene was heated to about 120° C.

Over a 6 hour period a solution of 21 g. (0.21 mole) of triethylaminedissolved in 10 ml. of xylene was added to the stirred solution at theabove temperature. The solution was stirred and heated at 140° C.overnight (about 15 hours). The cooled solution (about 0° C.) wasfiltered to remove the solid triethylamine hydrochloride which waswashed with fresh xylene and the washings added to the filtrate.

The solvent was removed from the combined filtrate and washings in arotary evaporator at about 15 mm. of mercury pressure and a temperatureof 70° C. An oily residue of wt.=34.3 g. remained. It was vacuumdistilled using the apparatus described in Example 1 and under apressure of 0.05 mm. of mercury. The first fraction, b.p.=65° to 70° C.,wt.=3.2 g. was an 18 percent recovery of the starting 2,4-toluenediisocyanate. The second fraction had a b.p.=145°-150° C., (wt.=9.5 g.)and was recovered as an oil representing a 35 percent yield of anisocyanato-azetidinedione mixture of the two isomers (a)N-(3-isocyanato-4-methylphenyl)-3,3-diethyl-azetidine-2,4-dione and (b)N-(3-isocyanato-6-methyl-phenyl)-3,3-diethylazetidine-2,4-dione inaccordance with the present invention and having the formulae ##STR13##

Infrared for the mixture (Neat) (in cm⁻¹): 2952, 2915, 2860, 2255(s),1861, 1840, 1735(s), 1600, 1570, 1510, 1455, 1380, 1040.

Proton NMR for the mixture (CDCl₃): δ 7.65 (m,1), 7.40-7.18 (m,2), 2.40(s,3), 1.86 (m,4), 1.13 (m,6).

The relative proportions of (a) to (b) in the mixture could not bedetermined with the same precision as in the previous Example 1 becauseof the more complex resonance of the ethyl groups. However, isomer (a)was assumed to be in excess because of lower steric hindrance in (a) asopposed to (b).

EXAMPLE 3

Using a similar procedure and apparatus as described in Example 1, astirred solution of 52.0 g. (0.3 mole) of 2,4-toluene diisocyanate and25 g. (0.15 mole) of 2-ethylhexanoyl chloride dissolved in 450 ml. ofxylene was heated to 138° to 145° C.

Over a period of 4 to 5 hours a solution of 30.0 g. (0.3 mole) oftriethylamine dissolved in 20 ml. of xylene was added to the stirredsolution at the above temperature. The solution was stirred and heatedwithin the above temperature range for an additional 2 hour period. Thesolution was cooled to about 0° C. and the precipitated triethylaminehydrochloride was removed by filtration. The precipitate was washed withfresh xylene which was added to the filtrate.

The solvent was removed from the combined filtrate and washings in arotary evaporator at about 15 mm. of mercury pressure and a temperatureof 70° C. An oily residue, wt.=84.1 g. was obtained. The residue wasdistilled using the apparatus described in Example 1 and under apressure of 0.1 mm. of mercury. The first fraction, b.p.=60° to 110° C.,wt.=32.7 g. was a 63 percent recovery of the starting 2,4-toluenediisocyanate. The second fraction, b.p.=130 to 160° C., wt.=34.2 g., wasisolated as an oil and represented a 76 percent yield of anisocyanato-azetidinedione mixture of the two isomers (a)N-(3-isocyanato-4-methylphenyl)-3-ethyl-3-butylazetidine-2,4-dione and(b) N-(3-isocyanato-6-methylphenyl)-3-ethyl-3-butylazetidine-2,4-dionein accordance with the present invention and having the formulae##STR14##

Infrared for the mixture (CCl₄) (in cm⁻¹): 2960, 2940, 2865, 2275(s),1862, 1740(s), 1613, 1580, 1520, 1460, 1382.

Proton NMR for the mixture (CDCl₃): 6 7.60 (m,l), 6.90-7.20 (m,2),2.38(s,3), δ 2.10-0.90 (m,14).

Elemental analysis for the mixture: Calculated for C₁₇ H₂₀ N₂ O₃ :C=67.98%, H=6.71%, N=9.33%; Found: C=68.02%, H=6.54%, N=9.42%. Similarlyto Example 2 above, the relative proportions of (a) to (b) in themixture could not be determined with precision but isomer (a) wasassumed to be the major component.

EXAMPLE 4

Using a similar procedure and apparatus as described in the previousexamples, a stirred solution of 50 g. (0.2 mole) of4,4'-methylenebis(phenyl isocyanate) and 16 g. (0.15 mole) of isobutyrylchloride dissolved in 250 ml. of xylene was heated to about 120° C.

Over a 3 hour period a solution of 25 g. (0.25 mole) of triethylaminedissolved in 20 ml. of xylene was added to the stirred solution at theabove temperature. The heating and stirring was continued for a further3 hour period. The solution was cooled to about 0° C. and the solidtriethylamine hydrochloride was removed by filtration and washed withfresh xylene which latter was added to the filtrate

The solvent was removed from the combined filtrate and washings in arotary evaporator at about 15 mm. of mercury pressure and a temperatureof 70° C. A solid residue was obtained, wt.=55.1 g. This residue wasrecrystallized from 80 ml. of cyclohexane to provide 13.3 g. ofcrystalline solid, m.p.=100° C. representing a 27 percent yield of4-isocyanato-4'-(3,3-dimethyl-2,4-dioxo-azetidino)diphenylmethane inaccordance with the present invention and having the formula ##STR15##

Elemental analysis: Calculated for C₁₉ H₁₆ N₂ O₃ : C=71.24%, H=5.02%,N=8.74%; Found: C=71.76%, H=4.67%, N=8.87%.

Infrared (CCl₄) (in cm⁻¹): 2955, 2910, 2255(s), 1852, 1743(s), 1601,1512(s), 1390, 1368.

Proton NMR (CDCl₃): δ 7.71 (d,2), 7.14 (d,2), 7.02 (s,4), 3.93 (s,2),1.46 (s,6).

EXAMPLE 5

Using a similar procedure and apparatus as described in the previousexamples a stirred solution of 20 g. (0.12 mole) of hexamethylenediisocyanate and 30 g. (0.28 mole) of isobutyryl chloride dissolved in150 ml. of xylene was heated to about 120° C.

Over an 8 hour period a solution of 35 g. (0.34 mole) of triethylaminedissolved in 30 ml. of xylene was added to the stirred solution at theabove temperature. The heating and stirring was continued overnight(about 16 hours). After about 24 hours of heating, the reaction solutionwas cooled to about 0° C. and the precipitated triethylaminehydrochloride was removed by filtration and washed with fresh xylenewhich was combined with the filtrate.

The solvent was removed from the combined filtrate and washings in arotary evaporator at about 15 mm. of mercury pressure and a temperatureof 80° C. A residue of an oil remained which was vacuum distilled usingthe apparatus described in Example 1 and under a pressure of 0.1 mm. ofmercury. A fore-fraction had a b.p.=50°-85° C. The main fraction had ab.p.=115°-120° C. and wt.=6.5 g. and remained a liquid representing a 22percent yield of N-(6-isocyanatohexyl)-3,3-dimethylazetidine-2,4-dionein accordance with the present invention and having the formula##STR16##

Infrared (Neat) (in cm⁻¹): 2920, 2850, 2255(s), 1721(s), 1450, 1435,1390, 1350, 1250.

Proton NMR (CDCl₃): δ 3.32 (4,t), 2.0-1.0 (8,m), 1.38 (6,s).

EXAMPLE 6

Using a similar procedure and apparatus as described in the previousexamples, a stirred solution consisting of 14.5 g. (0.106 eq.) of apolymethylene polyphenyl polyisocyanate mixture (isocyanate equiv.=137)containing about 40 to 45 percent by weight of methylenebis(phenylisocyanate) and the remainder of said mixture consisting ofpolymethylene polyphenyl polyisocyanates having a functionality greaterthan 2, and 8.2 g. (0.05 mole) of 2-ethylhexanoyl chloride dissolved in100 ml. of xylene was stirred and heated to 140° C.

Over a 2.5 hour period a solution of 7.5 g. (0.075 mole) oftriethylamine dissolved in 20 ml. of xylene was added to the stirredsolution at the above temperature. Stirring of the solution at 140° C.was continued for another 6 hours during which time the progress of thereaction was followed by infrared analysis on aliquot samples. Thecharacteristic acid chloride absorption at 1785 cm⁻¹ disappeared and thetwo characteristic absorptions at 1740 and 1845 cm⁻¹ due to theazetidine-2,4-dione ring increased during the reaction period.

The reaction solution was cooled to about 0° C. and the precipitatedtriethylamine hydrochloride was removed by filtration. The filtrate washeated in a rotary evaporator at about 10 mm. of mercury pressurefollowed by higher vacuum (about 0.15 mm.) to remove all the solvent. Anoily residue, wt.=21.8 g. was obtained; infrared analysis showed thecharacteristic azetidinedione

absorption at 1740 and 1845 cm-:; isocyanate equiv. wt.=294(theor.=267). This residue represented a 97 percent yield of anisocyanato-azetidinedione in accordance with the present inventionhaving the representative formula ##STR17##

EXAMPLE 7

A 250 ml. reaction flask equipped with a magnetic stirrer, refluxcondenser, and thermometer was charged with 25.0 g. (0.10 mole) of theisocyanato-azetidinedione mixture prepared in accordance with Example 1above, 0.15 g. of a trimerization catalyst comprising about 67 percentby weight of potassium 2-ethylhexanoate dissolved in a polypropyleneglycol of about 400 MW, and 32 ml. of ethyl acetate.

The solution was stirred and heated under reflux (reaction temperatureof about 80° C.). Aliquot samples were removed periodically for infraredspectrum analysis to determine the progress of the trimerization of theisocyanate groups, i.e. their disappearance. After 12 hours the reactionwas terminated as the isocyanate was totally consumed.

The reaction solution was poured into 150 ml. of ethyl acetate andwashed with water in a separatory funnel to remove the catalyst from theproduct which latter remained in the organic solution. The organic layerwas dried by storage over magnesium sulfate. The solution was filteredto remove the magnesium sulfate and was then heated in a rotaryevaporator under about 15 mm. of mercury pressure to remove the ethylacetate. The residue was a yellow colored resinous fluid when warm andwhich was dried further under 10 mm. of mercury pressure and 60° C. Theproduct solidified to an amber colored resinous solid which waspulverized to pale yellow powder, wt.=24.5 g., melted at 200° to 260° C.representing a 98 percent yield of an azetidinedione-isocyanuratemixture in accordance with the present invention and represented by theformula ##STR18## and mixtures of these groups in the same molecule.

Elemental analysis: Calculated for C₃₉ H₃₆ N₆ O₉ : C=63.93%, H=4.95%,N=11.47%; Found: C=63.58%, H=5.38%, N=11.17%.

Infrared (CCl₄) (in cm⁻¹): 3015, 2975, 2930, 2865, 1860, 1745(s),1718(s), 1511, 1405, 1140, 1050.

When the same reactants as above but in smaller proportions (4.8 g. ofthe isocyanato-azetidinedione and 0.12 g. of the trimerization catalystmixture) were reacted in 10 ml. of xylene at a temperature of about 120°C. the reaction was completed in 4 hours. The same solid resinousproduct was obtained.

EXAMPLE 8

Using the same apparatus and procedure set forth in Example 7 above, a5.0 g. sample (0.02 mole) of the isocyanato-azetidinedione mixtureprepared in accordance with Example 3 above was stirred and heated underreflux with 0.12 g. of the same trimerization catalyst used in Example 7in 15 ml. of ethyl acetate.

After 18 hours the trimerization was complete as no more isocyanateabsorption could be observed by infrared analysis. The solution wasdiluted to 50 ml. of ethyl acetate and washed with three separateportions of water in a separatory funnel. The organic layer wasseparated and dried over magnesium sulfate. After separating the dryingagent the solution was stripped of solvent in a rotary evaporator under10 mm. of mercury pressure. The residue was a resinous yellow solidwhich was easily pulverized (wt.=4.92 g.) and melted at 145° to 160° C.representing a 98 percent yield of an azetidinedioneisocyanurate mixturein accordance with the present invention and represented by the formula##STR19## and mixtures of these groups in the same molecule.

Infrared (CHCl₃) (in cm¹): 3020, 2965, 2945, 2875, 1860, 1742(s),1720(s), 1511, 1417(s), 1220, 1050.

EXAMPLE 9

The following experiment describes the preparation of a bis-urethane inaccordance with the present invention.

A 100 ml. reaction flask equipped with a magnetic stirrer, condenser,and thermometer was charged with 5.0 g. (0.02 mole) of anisocyanato-azetidinedione mixture prepared in accordance with Example 1above, 20.25 g. (0.01 mole) of a polyoxypropylene glycol having amolecular weight of about 2025, and about 0.035 g. of dibutyl tindilaurate (0.2 drop).

The mixture was heated at 90 to 95° C. for about 18 hours and resultedin a cloudy viscous liquid. Infrared analysis showed that all of theisocyanate was consumed and the absorptions at 1850 and 1740 cm⁻¹ due tothe azetidinedione ring remained intact. Gel permeation chromatography(GPC) in tetrahydrofuran solvent showed a single peak constitutinggreater than 95 percent by weight of the product mixture. Thus there wasobtained a bis-urethane having the representative formula ##STR20##

Using the same procedure and apparatus described above, 6.0 (0.02 mole)of an isocyanato-azetidinedione mixture prepared in accordance withExample 3 above, 20.23 g. (0.01 mole) of the same polyoxypropyleneglycol as above, and 0.12 g. of dibutyl tin dilaurate were heated at95°-100° C. for about 18 hours. Infrared analysis of the resulting clearviscous liquid showed complete consumption of isocyanate and theazetidinedione ring intact at 1860 and 1745 cm-: GPC analysis showed asingle peak amounting to greater than percent by weight of the productmixture Thus there was obtained a bis urethane in accordance with thepresent invention having the formula ##STR21##

EXAMPLE 10

A 100 ml. reaction flask equipped similarly to the one described inExample 9 was charged with 0.45 g. (0.005 mole) of 1,4-butanediol, 5 g.(0.01 mole) of an isocyanato-azetidinedione mixture prepared inaccordance with Example 1, 0.1 g. of dibutyl tin dilaurate, and ml. ofethyl acetate.

The mixture was stirred and heated at 80° to 90° C. for about 24 hours.Upon cooling a precipitate formed and was collected on a suction filter,washed with fresh ethyl acetate and thoroughly dried; wt.=1.45 g.,m.p.=220° to 222° C.

Thus there was obtained a bis urethane in accordance with the presentinvention having the formula ##STR22##

Infrared (CHCl₃) (in cm⁻¹) 3450, 3016, 2975, 1860, 1744, 1590, 1535,1485, 1460, 1400, 1378, 1060.

Proton NMR (CDCl₃): δ 7.50-7.0 (m,6), 6.45 (s,2), 4.20 (t,4), 2.17(s,6), 1.74 (t,4), 1.40 (s,12).

Elemental analysis: Calculated for C₃₀ H₃₄ N₄ O₈ : C=62.22%, H=5.92%,N=9.68%; Found: C=62.12%, H=6.12%, N=9.63%.

EXAMPLE 11

A 100 ml. reaction flask equipped according to Example 9 was chargedwith 0.90 g. (0.007 mole) of trimethylolpropane, 6.0 g. (0.02 mole) ofan isocyanatoazetidinedione mixture prepared in accordance with Example3 above, 0.1 g. of dibutyl tin dilaurate, and 10 ml. of ethyl acetate.

The mixture was stirred and heated at 80° to 90° C. for about 24 hours.No precipitate formed upon cooling the reaction solution The solvent wasremoved using a rotary evaporator under about 10 mm of mercury pressureto yield a resinous solid; m.p. greater than 70° C.

Thus there was obtained a tris urethane in accordance with the presentinvention having the formula ##STR23##

Infrared (CHCl₃) (in cm⁻¹): 3430, 3018, 2970, 2940, 2875, 1855, 1740(s),1620, 1590, 1530, 1460, 1391.

Elemental analysis: Calculated for C₅₇ H₇₄ N₆ O₁₂ : C=66.13%, H=7.21%,N=12%, Found: C=66.04%, H=7.45%, N=8.09%.

I claim:
 1. An azetidinedione urethane having the formula

    (A--NHCOO).sub.m R.sub.2

wherein each A represents the group ##STR24## wherein R and R₁, when taken individually, are independently selected from the group consisting of hydrogen and hydrocarbyl having from 1 to 18 carbon atoms, and, when taken together with the carbon atom to which they are attached, represent a cycloalkane residue having 4 to 6 ring carbon atoms, inclusive, X is a divalent hydrocarbon radical having from 2 to 36 carbon atoms and divalent radicals having the formula ##STR25## wherein V is selected from the group consisting of --CO--, --O--, --SO₂ --, and alkylene having 1 to 4 carbon atoms, m has a value falling within the range of from about 1 to about 8, and R₂ is the residue of a primary or secondary hydroxyl compound having a molecular weight from about 32 to about 5000 and selected from the group consisting of aliphatic, aromatic, and cycloaliphatic mono-alcohols and polyols having a functionality of from 2 to
 8. 2. An azetidinedione-urethane according to claim 1 wherein R and R₁ are the same or different alkyl.
 3. An azetidinedione-urethane according to claim 1 wherein X is selected from the group consisting of arylene and divalent radicals having the formula ##STR26## wherein V is selected from the group consisting of --CO--, --O--, --SO₂ --, and alkylene having 1 to 4 carbon atoms, inclusive.
 4. An azetidinedione-urethane according to claim 1 wherein m equals
 2. 5. An azetidinedione-urethane according to claim 1 having the formula ##STR27##
 6. An azetidinedione-urethane according to claim 1 having the formula ##STR28##
 7. An azetidinedione-urethane according to claim 1 having the formula ##STR29##
 8. An azetidinedione-urethane according to claim 1 having the formula ##STR30## 